CURSES_SCREEN(3) | Library Functions Manual | CURSES_SCREEN(3)

# NAME

curses_screen, newterm, set_term, delscreen, endwin, initscr, isendwin, resizeterm, setterm — curses terminal and screen routines

# LIBRARY

Curses Library (libcurses, -lcurses)

# SYNOPSIS

#include <curses.h>

SCREEN *
newterm(char *type, FILE *outfd, FILE *infd);

SCREEN *
set_term(SCREEN *screen);

void
delscreen(SCREEN *screen);

int
endwin(void);

WINDOW *
initscr(void);

bool
isendwin(void);

int
resizeterm(int lines, int cols);

int
setterm(char *name);

extern int LINES;

extern int COLS;

# DESCRIPTION

These functions initialize terminals and screens.

The newterm() function initialises the curses data structures and pointers ready for use by curses. The type argument points to a terminfo(5) entry, or it may be NULL in which case the TERM environment variable is used. The outfd and infd are the output and input file descriptors for the terminal. The newterm() function must only be called once per terminal.

The set_term() function can be used to switch between the screens defined by calling newterm(), a pointer to the previous screen structure that was in use will be returned on success.

Calling delscreen() will destroy the given screen and free all allocated resources.

Calling endwin() will end the curses session and restore the saved terminal settings.

The curses session must be initialised by calling initscr() which saves the current terminal state and sets up the terminal and internal data structures to support the curses application. This function call must be, with few exceptions, the first Curses library call made. The exception to this rule is the newterm() call which may be called prior to initscr(). The size of the curses screen is determined by checking the tty(4) size and then the terminfo(5) entries for the terminal type. If the environment variables LINES or COLS are set, then these will be used instead.

When either newterm() or initscr() are called, the Curses library sets up signal handlers for SIGTSTP and SIGWINCH. If a signal handler is already installed for SIGWINCH, this will also be called when the Curses library handler is called.

The isendwin() function can be used to determine whether or not a refresh of the screen has occurred since the last call to endwin().

The size of the screen may be changed by calling resizeterm() with the updated number of lines and columns. This will resize the curses internal data structures to accommodate the changed terminal geometry. The curscr and stdscr windows and any of their subwindows will be resized to fit the new screen size. The application must redraw the screen after a call to resizeterm().

The setterm() function sets the terminal type for the current screen to the one passed, initialising all the curses internal data structures with information related to the named terminal. The name argument must be a valid name or alias in the terminfo(5) database for this function to succeed.

# RETURN VALUES

Functions returning pointers will return NULL if an error is detected. The functions that return an int will return one of the following values:

OK
  The function completed successfully.
ERR
  An error occurred in the function.

# SEE ALSO

curses_window(3), tty(4), terminfo(5), signal(7)

# STANDARDS

The NetBSD Curses library complies with the X/Open Curses specification, part of the Single Unix Specification.

# HISTORY

The Curses package appeared in 4.0BSD. The resizeterm() function is a ncurses extension to the Curses library and was added in NetBSD 1.6.

April 5, 2012 | NetBSD 7.2